This is good form for datastructures, so caller can track weird bugs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
/* Licensed under LGPLv2.1+ - see LICENSE file for details */
#include <ccan/dgraph/dgraph.h>
#include <stdlib.h>
+#include <stdio.h>
void dgraph_init_node(struct dgraph_node *n)
{
struct dgraph_edge *e;
unsigned int i;
+ (void)dgraph_debug(n);
for (i = DGRAPH_FROM; i <= DGRAPH_TO; i++) {
while ((e = tlist_top(&n->edge[i], list[i])) != NULL) {
assert(e->n[i] == n);
void dgraph_add_edge(struct dgraph_node *from, struct dgraph_node *to)
{
struct dgraph_edge *e = malloc(sizeof(*e));
+
+ (void)dgraph_debug(from);
+ (void)dgraph_debug(to);
e->n[DGRAPH_FROM] = from;
e->n[DGRAPH_TO] = to;
tlist_add(&from->edge[DGRAPH_FROM], e, list[DGRAPH_FROM]);
{
struct dgraph_edge *e, *next;
+ (void)dgraph_debug(from);
+ (void)dgraph_debug(to);
dgraph_for_each_edge_safe(from, e, next, DGRAPH_FROM) {
if (e->n[DGRAPH_TO] == to) {
free_edge(e);
{
struct dgraph_edge *e, *next;
- dgraph_for_each_edge_safe(n, e, next, dir) {
+ /* dgraph_for_each_edge_safe, without dgraph_debug() */
+ tlist_for_each_safe(&n->edge[dir], e, next, list[dir]) {
if (!traverse_depth_first(e->n[!dir], dir, fn, data))
return false;
}
return fn(n, (void *)data);
}
-void dgraph_traverse(struct dgraph_node *n,
+void dgraph_traverse(const struct dgraph_node *n,
enum dgraph_dir dir,
bool (*fn)(struct dgraph_node *, void *),
const void *data)
{
struct dgraph_edge *e, *next;
- dgraph_for_each_edge_safe(n, e, next, dir) {
+ /* dgraph_for_each_edge_safe, without dgraph_debug() */
+ tlist_for_each_safe(&n->edge[dir], e, next, list[dir]) {
if (!traverse_depth_first(e->n[!dir], dir, fn, data))
break;
}
}
+
+struct check_info {
+ const struct dgraph_node *ret;
+ const char *abortstr;
+};
+
+static bool find_backedge(const struct dgraph_node *from,
+ const struct dgraph_node *to,
+ enum dgraph_dir dir)
+{
+ struct dgraph_edge *e;
+
+ tlist_for_each(&from->edge[dir], e, list[dir]) {
+ if (e->n[!dir] == to)
+ return true;
+ }
+ return false;
+}
+
+static bool dgraph_check_node(struct dgraph_node *n, void *info_)
+{
+ struct check_info *info = info_;
+ unsigned int dir;
+ struct dgraph_edge *e;
+
+ for (dir = DGRAPH_FROM; dir <= DGRAPH_TO; dir++) {
+ /* First, check edges list. */
+ if (!tlist_check(&n->edge[dir], info->abortstr)) {
+ info->ret = NULL;
+ return false;
+ }
+
+ /* dgraph_for_each_edge() without check! */
+ tlist_for_each(&n->edge[dir], e, list[dir]) {
+ if (e->n[dir] == n) {
+ if (find_backedge(e->n[!dir], n, !dir))
+ continue;
+ if (info->abortstr) {
+ fprintf(stderr,
+ "%s: node %p %s edge doesnt"
+ " point back to %p\n",
+ info->abortstr, e->n[!dir],
+ !dir == DGRAPH_FROM
+ ? "DGRAPH_FROM" : "DGRAPH_TO",
+ n);
+ abort();
+ }
+ info->ret = NULL;
+ return false;
+ }
+
+ if (info->abortstr) {
+ fprintf(stderr,
+ "%s: node %p %s edge %p points"
+ " to %p\n",
+ info->abortstr, n,
+ dir == DGRAPH_FROM
+ ? "DGRAPH_FROM" : "DGRAPH_TO",
+ e, e->n[dir]);
+ abort();
+ }
+ info->ret = NULL;
+ return false;
+ }
+ }
+
+ return true;
+}
+
+struct dgraph_node *dgraph_check(const struct dgraph_node *n,
+ const char *abortstr)
+{
+ struct check_info info;
+
+ /* This gets set to NULL by dgraph_check_node on failure. */
+ info.ret = n;
+ info.abortstr = abortstr;
+
+ dgraph_check_node((struct dgraph_node *)info.ret, &info);
+
+ if (info.ret)
+ dgraph_traverse(n, DGRAPH_FROM, dgraph_check_node, &info);
+ if (info.ret)
+ dgraph_traverse(n, DGRAPH_TO, dgraph_check_node, &info);
+ return (void *)info.ret;
+}
void dgraph_add_edge(struct dgraph_node *from, struct dgraph_node *to);
bool dgraph_del_edge(struct dgraph_node *from, struct dgraph_node *to);
+#ifdef CCAN_DGRAPH_DEBUG
+#define dgraph_debug(n) dgraph_check((n), __func__)
+#else
+#define dgraph_debug(n) (n)
+#endif
+
/* You can dgraph_clear_node() the node you're on safely. */
#define dgraph_traverse_from(n, fn, arg) \
- dgraph_traverse((n), DGRAPH_FROM, \
+ dgraph_traverse(dgraph_debug(n), DGRAPH_FROM, \
typesafe_cb_preargs(bool, void *, (fn), (arg), \
struct dgraph_node *), \
(arg))
#define dgraph_traverse_to(n, fn, arg) \
- dgraph_traverse((n), DGRAPH_TO, \
+ dgraph_traverse(dgraph_debug(n), DGRAPH_TO, \
typesafe_cb_preargs(bool, void *, (fn), (arg), \
struct dgraph_node *), \
(arg))
-void dgraph_traverse(struct dgraph_node *n,
+void dgraph_traverse(const struct dgraph_node *n,
enum dgraph_dir dir,
bool (*fn)(struct dgraph_node *from, void *data),
const void *data);
#define dgraph_for_each_edge(n, i, dir) \
- tlist_for_each(&(n)->edge[dir], i, list[dir])
+ tlist_for_each(&dgraph_debug(n)->edge[dir], i, list[dir])
#define dgraph_for_each_edge_safe(n, i, next, dir) \
- tlist_for_each_safe(&(n)->edge[dir], i, next, list[dir])
+ tlist_for_each_safe(&dgraph_debug(n)->edge[dir], i, next, list[dir])
+/**
+ * dgraph_check - check a graph for consistency
+ * @n: the dgraph_node to check.
+ * @abortstr: the string to print on aborting, or NULL.
+ *
+ * Returns @n if the list is consistent, NULL if not (it can never
+ * return NULL if @abortstr is set).
+ *
+ * See also: tlist_check()
+ */
+struct dgraph_node *dgraph_check(const struct dgraph_node *n,
+ const char *abortstr);
#endif /* CCAN_DGRAPH_H */
--- /dev/null
+#define CCAN_DGRAPH_DEBUG 1
+#include <ccan/dgraph/dgraph.h>
+/* Include the C files directly. */
+#include <ccan/dgraph/dgraph.c>
+#include <ccan/tap/tap.h>
+
+static bool count_nodes(struct dgraph_node *n, unsigned int *count)
+{
+ (*count)++;
+ return true;
+}
+
+static bool stop_traverse(struct dgraph_node *n, unsigned int *count)
+{
+ if (--(*count) == 0)
+ return false;
+ return true;
+}
+
+int main(void)
+{
+ struct dgraph_node n1, n2, n3;
+ unsigned int count = 0;
+
+ /* This is how many tests you plan to run */
+ plan_tests(42);
+
+ dgraph_init_node(&n1);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ count = 0;
+ dgraph_traverse_from(&n1, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_to(&n1, count_nodes, &count);
+ ok1(count == 0);
+
+ dgraph_init_node(&n2);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ dgraph_add_edge(&n1, &n2);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ count = 0;
+ dgraph_traverse_from(&n1, count_nodes, &count);
+ ok1(count == 1);
+ count = 0;
+ dgraph_traverse_to(&n1, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_from(&n2, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_to(&n2, count_nodes, &count);
+ ok1(count == 1);
+
+ dgraph_init_node(&n3);
+ ok1(dgraph_check(&n3, NULL) == &n3);
+ dgraph_add_edge(&n2, &n3);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ ok1(dgraph_check(&n3, NULL) == &n3);
+ count = 0;
+ dgraph_traverse_from(&n1, count_nodes, &count);
+ ok1(count == 2);
+ count = 0;
+ dgraph_traverse_to(&n1, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_from(&n2, count_nodes, &count);
+ ok1(count == 1);
+ count = 0;
+ dgraph_traverse_to(&n2, count_nodes, &count);
+ ok1(count == 1);
+ count = 0;
+ dgraph_traverse_from(&n3, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_to(&n3, count_nodes, &count);
+ ok1(count == 2);
+
+ /* Check stopping traverse. */
+ count = 1;
+ dgraph_traverse_from(&n1, stop_traverse, &count);
+ ok1(count == 0);
+ count = 2;
+ dgraph_traverse_from(&n1, stop_traverse, &count);
+ ok1(count == 0);
+ count = 3;
+ dgraph_traverse_from(&n1, stop_traverse, &count);
+ ok1(count == 1);
+
+ dgraph_clear_node(&n1);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ ok1(dgraph_check(&n3, NULL) == &n3);
+
+ count = 0;
+ dgraph_traverse_from(&n2, count_nodes, &count);
+ ok1(count == 1);
+ count = 0;
+ dgraph_traverse_to(&n2, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_from(&n3, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_to(&n3, count_nodes, &count);
+ ok1(count == 1);
+
+ ok1(dgraph_del_edge(&n2, &n3));
+ count = 0;
+ dgraph_traverse_from(&n2, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_to(&n2, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_from(&n3, count_nodes, &count);
+ ok1(count == 0);
+ count = 0;
+ dgraph_traverse_to(&n3, count_nodes, &count);
+ ok1(count == 0);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ ok1(dgraph_check(&n3, NULL) == &n3);
+
+ ok1(!dgraph_del_edge(&n2, &n3));
+ dgraph_clear_node(&n2);
+
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ ok1(dgraph_check(&n3, NULL) == &n3);
+
+ /* This exits depending on whether all tests passed */
+ return exit_status();
+}
unsigned int count = 0;
/* This is how many tests you plan to run */
- plan_tests(25);
+ plan_tests(42);
dgraph_init_node(&n1);
+ ok1(dgraph_check(&n1, NULL) == &n1);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 0);
ok1(count == 0);
dgraph_init_node(&n2);
+ ok1(dgraph_check(&n2, NULL) == &n2);
dgraph_add_edge(&n1, &n2);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 1);
ok1(count == 1);
dgraph_init_node(&n3);
+ ok1(dgraph_check(&n3, NULL) == &n3);
dgraph_add_edge(&n2, &n3);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ ok1(dgraph_check(&n3, NULL) == &n3);
count = 0;
dgraph_traverse_from(&n1, count_nodes, &count);
ok1(count == 2);
ok1(count == 1);
dgraph_clear_node(&n1);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ ok1(dgraph_check(&n3, NULL) == &n3);
count = 0;
dgraph_traverse_from(&n2, count_nodes, &count);
count = 0;
dgraph_traverse_to(&n3, count_nodes, &count);
ok1(count == 0);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ ok1(dgraph_check(&n3, NULL) == &n3);
ok1(!dgraph_del_edge(&n2, &n3));
dgraph_clear_node(&n2);
+ ok1(dgraph_check(&n1, NULL) == &n1);
+ ok1(dgraph_check(&n2, NULL) == &n2);
+ ok1(dgraph_check(&n3, NULL) == &n3);
+
/* This exits depending on whether all tests passed */
return exit_status();
}